Barn Owl adaptations

Slow-Mo Barn Owl in Flight – Unexpected Wilderness – BBC 
Robert MacFarlane admires a beautiful barn owl in flight and takes a look at a snowy Epping forest

Flight

  • Compared with most birds Barn Owls have a very low wing loading (large wings supporting a lightweight body).
  • This means they are able to fly very slowly without stalling and hover in only the slightest lift (rising air).
  • Slow flight gives the birds ample time to locate and pinpoint prey on the ground below.
  • Low wing loading enables them to pass through the air very gently and hover with minimal effort.

Feathers

Barn Owl wing feather [Melanie Lindenthal]The owls’ feathers are very soft – another adaptation for quiet flight;

  • The flight feathers are covered in a thin hair-like structure that traps air within the feather surface. This helps to maintain a smooth air-flow across the wings and thereby avoid stalling at very low airspeeds.
  • The foremost wing feather (the 10th primary) also has a row of tiny hooks that help to deaden the sound of air hitting the wings’ leading edge.
  • Almost-silent flight enables the birds to hear the tiny sounds produced by their small mammal prey and approach them undetected.
  • Compared with other birds, Barn Owl feathers are not particularly waterproof.
  • They generally avoid hunting in rain as wet feathers increase noise and reduce efficiency.
  • See more close-up pictures of Barn Owl feathers.

Hearing

  • Barn Owl ear opening [Melanie Lindenthal]The Barn Owl’s heart-shaped face, or ‘facial disk’, collects and directs sound toward the inner ears.
  • The ear openings are situated inside the facial disk just behind the eyes.
  • They are shaped differently and placed asymmetrically, one higher than the other.
  • Sounds reaching the ears are therefore heard differently which helps the owl’s brain work out the exact position of the sound source.
  • The ears are particularly good at detecting the high frequency sounds emitted by small mammals moving in vegetation and vocalising.
  • Experiments have shown that Barn Owls are able to capture prey in total darkness by hearing alone.
  • This also comes in useful when trying to catch small mammals in deep cover.
  • Barn Owl hearing is the most sensitive of any animal ever tested!
  • Despite this they sometimes choose to roost and nest in very noisy places.

Eyesight

  • Barn Owl eyes and the facial disk [Melanie Lindenthal]Barn Owl eyes are, on average, twice as light sensitive as human eyes.
  • The owl’s low-light vision is highly movement sensitive.
  • Anything that moves is instantly noticed but anything that keeps still (and silent) is usually ignored.
  • Barn Owls take little notice of artificial lights and may even use them as an aid to hunting.
  • Sudden exposure to very bright lights (such as car headlights) in dark situations may cause brief visual impairment.
  • Their dark-adapted eyes also work well in full sunlight.

Barn Owl legs, toes and talons [Melanie Lindenthal]Legs, toes and talons

  • Barn Owls have remarkably long legs, toes and talons.
  • This helps them to catch prey at the base of deep vegetation.
  • The talons are extremely sharp and prey is thought to be killed by foot clenching rather than a peck.

 Camouflage

  • When viewed from above Barn Owls are quite well camouflaged.
  • TBarn Owl plumage is camouflage [Russell Savory]he rough grassland over which they usually hunt is, for most of the year, the same predominantly light brown colour as their upperparts.
  • The most plausible explanation for the Barn Owl’s white underside is that it works as an anti-silhouette strategy: birds almost always appear as a dark silhouette when viewed from below – so birds with paler underparts are less visible.

There is more information about this topic in the Barn Owl Conservation Handbook.

Take a look at our gallery of close-up pictures of Barn Owl anatomy.